1.Excluding stoppages, the speed of a bus is 54 kmph and including stoppages, it is 45 kmph. For how many minutes does the bus stop per hour?
A.10 min
B.12 min
C.18 min
D.15 min
E.None of these
Answer – A (10 min)
Explanation – Due to stoppages, it covers 9 km less.Time taken to cover 9 km = (9/54 x 60) min = 10 min
2.A motor car starts with the speed of 70 km/hr with its speed increasing every two hours by 10 kmph. In how many hours will it cover 345 kms?
A.4 hrs
B.4 hrs 5 mins
C.4 1/2 hrs
D.2 hrs
E.None of these
Answer – C (4 1/2 hrs)
Explanation – Distance covered in first 2 hours = (70 x 2) km = 140 km
Distance covered in next 2 hours = (80 x 2) km = 160 km
Remaining distance = 345 – (140 + 160) = 45 km.
Speed in the fifth hour = 90 km/hr
Time taken to cover 45 km = as speed is 90km/hr means it covers 90 km in 1 hour
so,if 90km………..1 hr
45km……….?
?=45/90hr=1/2hr
Total time taken = 2 + 2 +1/2=4 (1/2)hrs
3.A person travels from P to Q at a speed of 40 kmph and returns by increasing his speed by 50%. What is his average speed for the both the trips?
A.35 kmph
B.4o kmph
C.48 kmph
D.55 kmph
E.None of these
Answer – C (48 kmph)
Explanation – Speed on return trip = 150% of 40 = 60 kmph
Average speed =
[2 x 40 x 60] / [40 + 6]km/hr =4800/100km/hr = 48 km/hr.
4.Three trains are running from a place A to another place B. Their speeds are in the ratio of 4 : 3 : 5. The time ratio to reach B by trains will be
A. 4 : 3 : 5
B. 5 : 3 : 4
C. 15 : 9 : 20
D. 15 : 20 : 12
Answer: D(15 : 20 : 12)
Explanation: Ratio of speeds = 4 : 3 : 5
Therefore Ratio of times taken [t=d/s or t indirectly proportional to s when distance is same]= (1/4) : (1/3) : (1/5) = 15 : 20 : 12
5.A man in a train notices that he can count 21 telephone posts in one minute. If they are known to be 50 meters apart, then at what speed is the train travelling?
A.50 kmph
B.54 kmph
C.60 kmph
D.62 kmph
E.None of these
Answer – C (60 kmph)
Explanation – Number of gaps between 21 telephone posts = 20 Distance traveled in 1 minute = (50 x 20) m = 1000 m = 1 km
Speed = 60 km/hr
A.10 min
B.12 min
C.18 min
D.15 min
E.None of these
Answer – A (10 min)
Explanation – Due to stoppages, it covers 9 km less.Time taken to cover 9 km = (9/54 x 60) min = 10 min
2.A motor car starts with the speed of 70 km/hr with its speed increasing every two hours by 10 kmph. In how many hours will it cover 345 kms?
A.4 hrs
B.4 hrs 5 mins
C.4 1/2 hrs
D.2 hrs
E.None of these
Answer – C (4 1/2 hrs)
Explanation – Distance covered in first 2 hours = (70 x 2) km = 140 km
Distance covered in next 2 hours = (80 x 2) km = 160 km
Remaining distance = 345 – (140 + 160) = 45 km.
Speed in the fifth hour = 90 km/hr
Time taken to cover 45 km = as speed is 90km/hr means it covers 90 km in 1 hour
so,if 90km………..1 hr
45km……….?
?=45/90hr=1/2hr
Total time taken = 2 + 2 +1/2=4 (1/2)hrs
3.A person travels from P to Q at a speed of 40 kmph and returns by increasing his speed by 50%. What is his average speed for the both the trips?
A.35 kmph
B.4o kmph
C.48 kmph
D.55 kmph
E.None of these
Answer – C (48 kmph)
Explanation – Speed on return trip = 150% of 40 = 60 kmph
Average speed =
[2 x 40 x 60] / [40 + 6]km/hr =4800/100km/hr = 48 km/hr.
4.Three trains are running from a place A to another place B. Their speeds are in the ratio of 4 : 3 : 5. The time ratio to reach B by trains will be
A. 4 : 3 : 5
B. 5 : 3 : 4
C. 15 : 9 : 20
D. 15 : 20 : 12
Answer: D(15 : 20 : 12)
Explanation: Ratio of speeds = 4 : 3 : 5
Therefore Ratio of times taken [t=d/s or t indirectly proportional to s when distance is same]= (1/4) : (1/3) : (1/5) = 15 : 20 : 12
5.A man in a train notices that he can count 21 telephone posts in one minute. If they are known to be 50 meters apart, then at what speed is the train travelling?
A.50 kmph
B.54 kmph
C.60 kmph
D.62 kmph
E.None of these
Answer – C (60 kmph)
Explanation – Number of gaps between 21 telephone posts = 20 Distance traveled in 1 minute = (50 x 20) m = 1000 m = 1 km
Speed = 60 km/hr
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